As studios aim to prolong the life of disc, Blu-ray Disc’s 1080p offering remains a main selling point. But more and more online services are offering 1080p versions of video content that aim to match that quality.

Both the PlayStation Network and the Xbox 360 offer 1080p video. Walmart’s Vudu movie service uses the 1080p HDX video format, which Walmart says “delivers the highest-quality true high-definition 1080p content available from any Internet, broadcast or satellite on-demand service.” Best Buy’s CinemaNow offers 1080p movies to owners of PCs with second-generation Intel Core processors. And Netflix, which began offering 1080p streaming in 2010, offers 1080p streaming on the new Apple TV, and has plans for 1080p streaming on the new iPad.

Yet for all the promises of a rich 1080p streaming or download experience, there are a number of reasons Blu-ray’s 1080p won’t be beat, according to Andy Parsons, SVP of corporate communications for Pioneer Electronics and chair of the Blu-ray Disc Association's promotion committee in the United States.

“Blu-ray Disc's high bandwidth and capacity allows for a comparatively luxurious data transfer rate and file size, since we don’t have to worry about irritating customers with excessively long download times or rapidly filling up their hard drives with multiple 3GB-plus files,” he said.

Streaming 1080p content doesn’t have the issue of file storage, and Walmart spokesman Ravi Jariwala said Vudu, the retailer’s digital movie service, said customers with sufficient bandwidth — about 4.5 Mbps — get full 1080p with 5.1 and 7.1. surround sound, with nearly zero buffering. More than half of Vudu’s offerings are in high-def.

“Customer response to our HD content has been incredibly positive. In fact, 60% of our customers watch movies in HD or HDX,” Jariwala said. “We are committed to offering customers the option of having a streaming experience that is on par with the best home video options available anywhere, which is why we have made the investment to offer such a large portion of our library in HDX 1080p format.”

Yet Parsons said he was “skeptical” of the ability of most American households to handle the roughly 4 Mbps to 5 Mbps transfer rate needed for highly compressed 1080p streams. A late-2011 study by content delivery company Pando Networks found that the average broadband speed in the U.S. was 4.93 Mbps. Unpredictable networks and data caps for heavy users by service providers are also concerns, Parsons noted.

“When we consider that Netflix alone can currently consume up to a third of the nation’s Internet capacity during peak times, adding 1080p to the mix does not seem like a viable option long term,” Parsons said. “Blu-ray Discs will never frustrate users with unexplained buffer under-run errors, do not rely on network service quality or availability, and contain the very best possible image and sound quality that a studio can deliver for a given title.”

Then there’s the compression question. Services offering 1080p go a number of different routes to compress the high-def content enough to get it through the available pipes and onto screens in proper fashion.

The new Apple TV and new iPad both support 1080p, and Apple is using H.264 video compression to keep 1080p iTunes videos small enough to be downloaded in a timely fashion. Netflix takes the same approach, and has licensed the video technology of encoding company EyeIO, to help cut down on the bandwidth of its streaming video. Vudu touts its HDX video technology as the “best available” for the Internet — optimized for 40-inch HDTVs — with double the resolution of others.

But even the best high-def streaming service can’t currently match the video bit rates offered by Blu-ray (maxing out at 40 Mbps), Parsons said. That means 1080p streaming video may have more blurring, noise and artifacts.

Ben Drawbaugh, high-def editor for Engadget.com, agreed with that point. “I’ve sat down to watch Vudu movies and been bothered by buffering. That has never happened to a Blu-ray,” he said. Though he did note that certain digital downloads have been comparable to Blu-ray for years, and that Vudu’s HDX and Xbox 360 1080p streaming rentals “are both close enough that they can be compared to Blu-ray.”

“In the end though, if you look close enough, Blu-ray still wins,” Drawbaugh said, adding that a dependable connection is what’s most needed to get a quality 1080p stream.

And while the quality of 1080p downloads and streaming may be inching closer to Blu-ray, there’s the question of how many consumers will be able to notice the difference between the two.

Russ Crupnick, SVP of industry analysis at The NPD Group, said a narrow group of consumers can tell the difference between Blu-ray and streaming or downloaded 1080p, and that the differences between the two are just too subtle.

“There’s good, really good and good enough,” he said. “I think they understand that Blu-ray provides the best picture quality. But they are watching a lot of movies and TV on DVDs, networks, DVRs and VOD options that aren’t optimized. And it’s good enough.”

Iljitsch van Beijnum, a writer for the tech-savvy publication Arts Technica, set out to compare iTunes 1080p downloads with the quality offered by the gold standard for high-def, Blu-ray Disc.

The result?

“Blu-ray has the capacity to store almost 10 times as much video information as Apple’s downloads, so it seemed a given that Blu-ray would look better,” he said. “Still, I expected the iTunes 1080p downloads to look good, but for the most part they still managed to surpass my expectations.”

A 3.62GB 1080p iTunes download of 30 Days of Night held its own for the most part, van Beijnum said, offering HDTV-owning fans a hopeful taste that downloadable and streaming high-def content can match what’s offered with Blu-ray.

Yet while van Beijnum’s iTunes test bodes well for Apple’s 1080p content (Apple did not respond to a request for comment), he said most discerning customers should be able to tell the difference, and Blu-ray should always win.

For Parsons, he doesn’t consider it an “us vs. them” situation. He’s bought 1080p electronic sellthrough content for his new iPad, even though he already owns the same movie on Blu-ray.

“They can effectively coexist in my library, as they serve different purposes,” he said. “There is no doubt that online distribution of video content is useful and convenient. But as we in the BDA have always said, online seems best suited for casual, individual viewing of content, where occasional network disruptions are not nearly as impactful as they are during maximum-impact home theater viewing.